Maybe its becuase thier is a difference between "opinion" and "thoughts."

"Opinons" are a personal view: the view somebody takes about a certain issue, especially when it is based solely on personal judgment. "Opinons" are usually a fairly well thought out view of a specific case wether truly informed or not. The individual has dedicated some time to the thought therefore forming an "opinion." therefore its worth more to the individual giving it. 2 cents

"Thoughts" are the process of considering: the process of applying the mind to thinking about a particular person or subject. An opinion usually isn't formed by this point of time in the thought process, but its getting there. Hence, only worth a penny.